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堆积体边坡在我国西南地区广泛分布,为深入研究其地震响应规律,设计完成了1∶50比尺的概化边坡离心振动台模型试验,分析4级不同强度地震连续作用下,风干堆积体边坡的加速度响应、边坡变形及其失稳模式。试验结果表明,堆积体边坡水平向PGA放大系数表现出了典型的高程放大效应与趋表放大效应。沿堆积体边坡高程方向,输入地震波频谱特性发生了明显改变,各测点加速度傅里叶谱的卓越频率随PGA增大而降低。考虑竖直向加速度放大效应的影响后,发现合放大系数与水平向夹角随高程有减小的趋势,反映了坡面处发生的波场分裂与波型转换现象。随地震波幅值的增大,水平向与竖直向PGA放大系数均先减小后增大。试验过程中观察发现在地震波加速度峰值达到0.216 g时堆积体边坡开始失稳,坡顶沉降明显,失稳模式以浅层崩滑为主。
In order to further study the law of seismic response, the slope of pile body is widely distributed in the southwest of China. The centrifugal bench model test of generalized slope with 1:50 scale is designed. After four different intensity earthquakes are continuously operated, Acceleration response of body slope, slope deformation and instability mode. The experimental results show that the amplification factor of horizontal PGA shows a typical elevation effect and a scale-up effect. Along the elevation of the slope, the spectral characteristics of the input seismic wave have changed obviously. The remarkable frequency of the acceleration Fourier spectrum at each measuring point decreases with the increase of PGA. Considering the effect of vertical acceleration amplification, it is found that the included amplification coefficient and horizontal angle decrease with elevation, which reflects the phenomenon of wave field splitting and wave conversion occurring on the slope. With the increase of seismic wave amplitude, the amplification factor of horizontal and vertical PGA firstly decreases and then increases. During the test, it was found that the slope of the pile began to lose its stability when the peak acceleration of seismic wave reached 0.216 g, and the settlement of the top of the slope was obvious. The main failure mode was shallow landslide.